Lab-related Salmonella outbreak sickens 24 in 16 states

The US Centers for Disease Control and Prevention (CDC) today announced a multistate Salmonella Typhimurium outbreak linked to microbiology laboratories that has sickened 24 people in 16 states. The infections have been associated with clinical, commercial, and teaching labs.

The same Salmonella strain has been previously tied to lab-related exposures in 2011 and 2014, according to whole-genome sequencing. Investigators used the PulseNet system, a DNA fingerprinting database, to identify illnesses that may be part of the outbreak.

Illnesses onsets range from Mar 17 to Jun 22, with patients varying in age from younger than 1 year to 57 years. Seventy-five percent of the patients are female, and, of 21 people with available information, 6 were hospitalized. No deaths have been reported. Of 13 people who were interviewed, 9 had lab exposures.

Those sickened in the outbreak reported behaviors during lab work that may have increased the risk of Salmonella infections, including not wearing gloves or lab coats, not washing hands, and using the same writing utensils and notebook outside of the laboratory.

After an outbreak in 2011, the CDC issued guidelines for handling microorganisms safely in teaching labs. In its announcement today the agency said the outbreak highlights the potential risk of Salmonella infection from working in microbiology labs, adding that all students and staff in clinical and teaching laboratories should receive safety training.Jul 19 CDC outbreak announcement

Animal study suggests mechanism for Ebola persistence in survivors

A study on tissue samples from rhesus monkeys that had been previously infected with Ebola to test vaccines and treatments has revealed new clues about how the virus hides out after recovery from the disease. Researchers from the US Army Medical Research Institute of Infectious Diseases (USAMRIID) reported their findings Jul 17 in Nature Microbiology.

In West Africa's Ebola outbreak, clinicians found that the virus persisted in immune-privileged areas such as they eye, brain, and testes, and transmission through infected semen of survivors sparked clusters of cases as the outbreak wound down. Also, survivors have reported lingering effects, such as vision problems, headaches, and joint pain.

Little was known, however, about the mechanism that allowed the virus to enter and persist in the immune-privileged areas.

Based on their examination of the monkey tissue samples, the researchers found that in animals with acute infection, Ebola mainly replicated in the blood vessels. In animals with longer disease progression, the virus spread to surrounding tissues in the immune-privileged sties. In survivors the virus migrated out of blood vessels and into specific locations within privileged sites.

In the eye, the virus was found in macrophages that have the CD68 surface protein, which researchers said could be where Ebola hides. The team also found that Ebola persists in the brain by breaking down the blood-brain barrier, triggering inflammation.

Xiankun Zeng, PhD, study coauthor, said in a USAMRIID press release, "This study lays the foundation for developing animal models of persistent Ebola virus infection in humans. What we observed in primates is quite similar to what happened during the outbreak—there were survivors with latent infection, but the virus was not detectable in the blood."

The authors said that the study hints that otherwise promising experimental therapies may not completely clear the virus, suggesting that a different approach may be needed for medical countermeasures.Jul 17 Nat Microbiolabstract Jul 17 USAMRIID press release

Syria reports 4 more polio cases

The World Health Organization (WHO) yesterday reported 4 more polio cases in Syria since its previous update on Jul 12, bringing to 27 the number of cases of circulating vaccine-derived poliovirus type 2 confirmed in the war-torn country.

The most recent case involved an 8-month-old, with paralysis reported on Jun 6. The child had received one dose of oral polio virus vaccine. Twenty-six cases, including the most recent, are from the Mayadeen district, Deir Ez-Zor governorate, and 1 case was in the Tell Abyad district, Raqqa governorate.

Vaccination campaigns with monovalent type-2 oral polio vaccine are planned for Jul 22. The WHO said there are enough supplies to vaccinate 448,000 children under the age of 5 in the two governorates.Jul 18 WHO situation report

Sri Lanka dengue outbreak overwhelms health system

In the wake of heavy rains and flooding, Sri Lanka is experiencing a large dengue outbreak dominated by serotype 2, which had been found only in low numbers in the country since 2009, the WHO said today. Through Jul 7, officials have reported 80,732 cases this year, 215 of them fatal.

The total is 4.3-fold higher than the average over the last 7 years for the same period. The disease is endemic in Sri Lanka, where surveillance has shown that peak months of May to July coincide with the southwestern monsoon, which starts in late April.

About 43% of the cases were reported in Western province. The flooding occurred in 15 of the country's 25 districts, affecting nearly 600,000 people. Aside from the rains, failure to clear rain-soaked garbage, standing water, and other mosquito breeding grounds have led to more cases in urban and suburban areas.

The WHO said it is supporting Sri Lanka's health ministry to help with the response. Facing overwhelmed health facilities, the ministry has asked for military support to increase the number of beds. Defense forces are also helping with vector control activities, and the army, police, and civil defense forces are helping with house-to-house visits in high-risk areas and are mobilizing communities for garbage disposal, cleaning of mosquito-breeding sites, and health education.

The WHO's Regional Office for South East Asia (SEARO) has organized a task force to help guide the response. Also, the WHO has deployed an epidemiologist, an entomologist, and two dengue management experts. The WHO's office in Sri Lanka has bought 50 fogging machines to assist with mosquito control.Jul 19 WHO statement

Measles warning issued for Europe as deaths noted in Bangladesh

Today the CDC warned travelers to Europe this summer to protect themselves against measles, as European officials have recorded 14,000 measles cases since January 2016.

"Most measles cases in the United States are the result of international travel," said Gary Brunette, MD, MPH, chief of the CDC's travelers' health program, in a press release. "Travelers get infected while abroad and bring the disease home. This can cause outbreaks here in the United States."

Currently the CDC has measles travel health notices for five European countries: France, Belgium, Germany, Italy, and Romania.

The agency recommends that all travelers make sure they're up to date on their measles vaccines, and allow 4 to 6 weeks between immunization and travel. Measles is highly contagious; 90% of those susceptible will contract the disease if exposed.

In other measles news, Bangladeshi officials have named measles as the cause of death of nine children in the Chittagong's Sitakunda Upazil province, according to bdnews24.com, a Web-based newspaper in the country. The children were reported dead from Jul 8 to Jul 12. None of the children, who were part of an indigenous tribe that does not attend school, had been immunized.Jul 19 CDC news releaseJul 17 bdnews24.com news story

CDC: 10 cases of AFM confirmed in the United States this year

The CDC said in a recent update that officials so far this year have reported 10 cases of acute flaccid myelitis (AFM), a rare and serious disease that can cause paralysis. In 2016, 144 people in 37 states were confirmed to have AFM.

AFM is not well understood by physicians and researchers, but the disease can develop after a virus attacks the nervous system, including the spinal cord. Since August of 2014, the CDC has reported an uptick of AFM cases in the United States that have no known cause. In 2014, 120 people had AFM. That number dropped to 21 in 2015 before rising again last year.

Cases often appear in children. Symptoms can mimic complications caused by a range of viruses, including polio, West Nile, and non-polio enteroviruses.

"CDC is actively investigating AFM cases and monitoring disease activity," the update said. "We are working closely with healthcare providers and state and local health departments to increase awareness for AFM and encourage sending information about AFM cases to CDC."Jul 3 CDC update